Hemangiopericytoma of renal pelvis--an unusual tumor in an adolescent.

Since the initial report of renal hemangiopericytoma in 1955, only 39 cases of this rare vascular neoplasm, involving the renal capsule, parenchyma, or sinus have been described in the world literature. Herein we describe a case of a 15-year-old adolescent boy with this tumor arising from right renal pelvis. A radical right nephrectomy was performed. Histologic and immunologic studies revealed a hemangiopericytoma of renal pelvis soft tissues. The patient did well postoperatively and remains disease-free at the present time.